Lack of finance - cannot grow, buy new premises, develop new prodcuts, purchase new tech or hire new staff due to this. Business may go bankrupt if unable to find cash to pay debts.
Legalities/laws that restrict what a business can do (e.g national minimum wage, no smokers in bars, no misleading products etc). They must comply with the law or face heavy penalties.
Interest rates are extra money you have to pay (e.g bank interest must be paid on a bank loan). Rates can increase/decrease depending on economic condition.